UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460 

## DEC 1 

### 3 2006 OFFICE OF PREVENTION, PESTICIDESAND TOXIC SUBSTANCES

MEMORANDUM

SUBJECT: AlternativesAnalysis for Antimycin A and Rotenone in Lakes and Streams 

### (DP# 3 10753 and 307400)
FROM: Monisha Kaul, Biologist 

### C; 

### !L'L?~~-' 

# /i f/.tui z Nicole Zinn, Biologist Biological Analysis Branch

John Faulkner, Economist Economic Analysis Branch 

# &$-
Biological and EconomicAnalysis Division (7503P)

THRU: Arnet Jones, Chief Biological Analysis Branch 

### Idr+upi-Lt\ Richard Keigwin, Acting Chief 

### ,Y-rx-' xL-"i"-i 

### , :p Economic Analysis Branch Biological and Economic Analysis Division (7503P)

TO: Lance Wormell, Chemical Review Manager Katie Hall, Chemical Review Manager Special Review and Reregistration Division (7508P)

Peer Review Panel: November 29,2006 Summary

Rotenone and antimycin A are the onlytwo broad spectrumpiscicides registered in the United States. Rotenone and antimycin A appear to have niche uses, although both can be applied in a variety of situations. In general, antimycinA isused to repopulate native, threatened, or endangered trout species in streamsby eliminating nonnative fish species, particularly in high-altitude alpine lakes and streams because it is effective in cold alpine waters and where pH is low. In addition, this piscicide may be used at low concentrations,which makes it easy to transport to isolated or hard to reach mountainousstreams. Rotenoneis most often used in standingwater, such as large lakes and reservoirs. It is often applied to maintain sport fisheries, sample fishpopulations, and in rearing ponds. The costs ofrotenone and antimycin A are similar. For sampling fish populations alternativesto rotenone, such as electrofishing, appear to be available. However, for water bodies requiring selective or complete kill of certain fish species, rotenone and antimycin A are effective. Dewatering is effective for complete kill in a water body. In select cases, gill netting, which generally only reduces fish populations, has been used to remove all fish from certainmountain lakes in California. Although some uses ofrotenone and antimycin 

### A coincide, they are not complete replacement for each other because each has niche uses. Because there are no other broad spectrum piscicides available, the only possible alternatives are non-chemical fish control methods and none are applicable for all uses ofrotenone or antimycin A. 

### In situations where dewateringor electrofishing are potential replacements, it is not clear if these are more cost effective methods. Background

BEAD has conducted an alternatives analysis for antimycin A and rotenone as part ofthe risk mitigation and reregistrationprocess. Occupational and ecologicalrisks of concern were identified for rotenone primarily associated with inhalation ofthe dust formulation, contamination ofthe liquid formulationswith trichloroethyleneand the strongreliance of the formulated end product on aromatichydrocarbons. Risks of concern for antimycin 

### A
were not identifiedbecauseHED did not conduct a quantitative risk assessment due to the absence of data; however, the concerns for formulated endproduct were not as great since antimycinis lessreliant on co-solvents. Antimycin A and rotenone are the only two EPA registered piscicides. The product Fintrolo, manufactured by Aquabiotics Corporation, contains the active ingredient antimycin A. It is an antibioticproduced fkom Streptomyces bacteria, which kills fish by blocking cellular respiration. Rotenone is derived from certain tropical plants in the Leguminosae family and also inhibits cellular respiration (Finlayson, et al., 2000; Ware, 2000). BEAD has evaluated the two registered piscicides as alternativesto each other and to other non-chemical fish control methods. 

### In the case ofrotenone, which may also be used to sample fish populations, BEAD reviewed several other sampling techniques available. Antimycin A Use and Usage Antimycin A is used to selectivelyor completely kill fish species from freshwater streams and shallow lakes and ponds. The FintrolB label recommends that it be applied to lakes and ponds by boat bailer or spray. Boat bailer and drip tube applications are useful for depths greater that 1 foot. Backpack sprayers may be used for isolated areas. Drip stations may be used for stream applications. Aircraft applications are not recommended accordingto the label. Antimycin A either completelyor selectively kills fishbased on the concentration used. Fish species and sizes also vary in their sensitivity. For example, the label indicates troutare more sensitive to antimycin than catfish. The label recommended concentrations range &om0.5 to 25 parts per billion (ppb) and varies based on the pH and temperature ofthe water. Therefore, the appropriateconcentration must be determined based on several factors. Completekills require concentrationsgreater than fiveppb. Bioassays
are required to determine the correct concentration, particularly for selective kills.

EPA proprietary data indicate that antimycin A accounts for less than fivepercent of the area treated with piscicides or 4,000 acre-treatments in 1998 and the total use was less than 200 pounds. 

### In addition,the primary use is for endangered fish repopulation efforts. More recent usage information is not available, although available publications indicate that limited quantities of antimycin A are available (Finlayson et al, 2000; Marking, 1992).

A common use for Antimycin A is to repopulate native, threatened, or endangeredtrout species to streamsby eliminatingnonnative fish species. Antimycin A is particularly usell in high alpine lakes and streams because it is effectivein cold alpine waters and where pH is low (Schenk, 2002; Stevens, 2001). In addition,this piscicide may be used at low concentrations,which makes it portable to isolated or hard to reach mountainous streams. Antimycin A is effective for removal ofunwanted salmonids,which is important for the reintroduction ofnative fish. Another advantageof antimycin A use in streams is that it may be neutralized it with potassium permanganatein downstream locations. A disadvantageis that multiple applicationsmay be needed because antimycin A breaks down quickly. In addition,potassium permanganate may be harmful to some fish.

Commercial catfish production is the primary form of aquaculturein the U.S (Mississippi State University Extension Service,2006) Antimycin A is can be used to remove unwanted scaled fish from catfish production ponds (Wynne, 2002). Catfish are less sensitiveto Antimycin A and therefore may be able to tolerate this piscicide, while other unwanted fish areremoved. Antimycin 

### A may alsobe used to remove unwanted fish without harming catfish in ponds used for recreational fishing (Cichra, 2003). Antimycin A has also been used for restoration of alkaline,hardwater streams in southwesternU.S. (Weedman et al., 2005). A stream restoration project in Arizona involving the removal of two nonnative fish, green sunfish and small mouth bass, used two formulations of antimycin A, a liquid concentrateand coated sand grains. Multiple applications at concentrationsof 50 to 100ppb were used to successfully remove the target fish.


### Rotenone Use and Usage

A U.S. and Canadian survey ofrotenone use was done to obtain information on rotenone use and usage, as well as determine other issues with its use, as part ofthe development process for the rotenone stewardshipplan for the Rotenone Stewardship Program (McClay, 2000). Responses were received from agencies in 48 states. Nearly all of the rotenone (97.5%) applied between 1 988 and 1997was applied to standing water.Rotenone was applied for a number of differentreasons. In terms ofnumber of treatments, rotenone was most commonlyused to maintain sport fisheries, sample fish populations, and in rearing ponds. In terms of amount of standing water treated, rotenone
was largelyused to maintain fisheries and to eradicate exotic species. In terms of length of flowing water treated, rotenone was used largelyto maintain fisheries, for disease eradication, and restoration of threatened and endangered species. (McClay, 2000) These
same uses ofpiscicides are described in the RotenoneUse in Fisheries Management: Administrative and Technical GuidelinesManual (Finlayson et al, 2000).

Pounds ofrotenone used were calculatedfrom the survey results. Between 1988 and 1997, approximately 209,000 lbs active ingredient (ai) were applied, including approximately46,000 lb ai for one particularly large project (McClay, 2000). According to sales data, approximately23,000 lb ai ofrotenone were applied in 1998. The main use site was catfish ponds in the south (EPA proprietary data, 1998).

The application rates found in various publications are also those found on rotenone labels. A Mississippipublication on farm pond use ofrotenone lists application rates between 0.025 and 0.150 ppm ai (Brunson, 2004). A South Carolina publication for rotenone suggests similarrates, with a range of 0.025 to 0.2 ppm, and for selective control suggests rates of 0.005 to 0.007 ppm ai rotenone (Whetstone, Smith, and Watson, 2001) The wide range of rates reflects the need to use higher rates to control certain fish species (Rotenone labels; Brunson, 2004; Whetstone, Smith, and Watson, 2001). The rotenone labels also list a preimpoundment treatment above dams which include higher rotenone rates of 0.15 to 0.25 ppm ai. The exception to these labels is prenfishm Grass Carp Management Bait (EPA Reg. # 655-795), which is designed specificallyto attract and kill grass carp. According to EPA source data, piscicide usage varies from year to year depending on the projects being done to remove fish. In 1998,less than 1percent of surface water acreage in the U.S. was treated with a piscicide, with nearly half ofthe treatments occurring in the South. Most applications occur in the fall. The method of application varies with the body of water treated. Lakes and reservoirs are treated by boat, streams with a drip applicator, and small water bodies by hand fi-omthe edge ofthe water body. Most piscicides sold are ofthe liquid formulation. For rotenone, the liquid formulation is primarily used by private applicators whereas the powder formulationis used by government agencies (EPA proprietary data, 1998). Fish species vary in their sensitivityto rotenone. Some species, such as catfish, are less susceptible to rotenone than other fish (Brunson, 2004). In addition, the rotenone labels statethat "factors such as pH, temperature, depth and turbidity will change effectiveness."

Rotenone can be used to sample fishpopulations and communities. Although rotenone has advantages over other samplingmethods, such as the ability to use to sample large streams, one disadvantageis that most fish will not survive (Finlayson et al, 2000).Like antimycinA, rotenone can be neutralized with potassium permanganate (Finlayson et al, 2000). 

### Alternatives Analysis

There are several methods that can be used to remove unwanted fish: electrofishing, angling, netting, or use ofpiscicides.
Piscicides The only available registered broad spectrum piscicides are antimycinA and rotenone.
Both rotenone and antimycin a may be used in fish ponds, although for different purposes. Antimycin A is used to selectivelycontrol certain fish species in ponds whereas rotenone is generallyused for reclamation,which involves removing all fish and then restocking with the desired fish species. In some cases, selective treatments with rotenone may be possible with certain application techniques or if the target fish species is particularly sensitiveto rotenone. (Wynne, 2002)

Rotenone is effective in larger water bodies where antimycin A is not. While rotenone is more effective at higher pH levels than antimycinA, it may degrade slower and may be
more harmful to non-target macroinvertebrates. Although antimycin A generally takes days to degrade, rather than days to weeks in the case ofrotenone, at high pH values it may degrade within hours (Lennon, et al., 1971). Another disadvantageofrotenone is that it may repel fishbecause it is detected by fish. Rotenone requires higher quantities
as compared to antimycin A, which limits its use in isolated areas because it is less portable. Both rotenone and antimycin A may cause temporary loss ofpotable water. AntimycinA may not be availableor registered in all states (Finlayson et al, 2000). Lampricides Two lampricides areregistered in the U.S. These chemicals are TFM (3-trifluoromethyl4-nitrophenol) and niclosamide. Both ofthese chemicals areregistered for the control of sea lampreys, and niclosamide is also registered for the control of snails. In general the lampricides, particularly TFM, do not kill fish, although some fish species may be susceptible (Great Lakes Fishery Commission, 2004). These lampricides are not expected to be alternativesto rotenone and antimycin A. Dewatering Dewatering an area and applicationofpiscicides are described as the only ways to eliminate all fish fi-oman area (McClay, 2000; Finlayson et al, 2000). However, dewatering may be detrimentalto non-target organisms or have other environmental consequences (Finlayson et al, 2000). Gill Netting There are severalmethods of fish netting. Gill netting is a common practice that may reduce but generally does not completely eliminate fishpopulations. Gill netting is not considered a complete alternativeto rotenone and antimycin A.As mentioned above, dewateringan area and applicationofpiscicides are often described
as the only ways to eliminate all fish from an area (McClay, 2000; Finlayson et al, 2000). However, in at least somemountain lakes, gill netting appears to be feasibleto eliminate fish. Gill netting causes fish to become trapped in a net, thus eliminating at least a part of the population from an ecosystem. Nets are available in different sizes, which may allow for some selectivity of species and within species. In one study it was possible to eliminate trout from a mountain lake in California over a two to three year period. However, gill netting was described 

### as not being feasible for all mountain lakes. Gill netting was successful at removing trout in the studybecause the lake is relatively small, not very deep, there was little stream flow into and out ofthe lake, and there was no fish stocking (Knapp and Matthews, 1998). In addition, gill netting may not be feasible in areas where non-target fish or other non-target organisms are present. A surveyof lakes
near the study area found that in 15to 20 percent ofthe lakes, gill netting may be a feasible alternative to eliminate trout. It was also noted that in lakes where gill netting is not feasible, removal oftrout would need to be done with rotenone (Knapp and Matthews, 1998). A subsequent presentation and discussionby Knapp indicated that intensive gill netting has been successfblin severalmountain lakes (Knapp, 2005). Netting may alsobe difficult to implement in mountainous stream settings and would need to be repeated only to keep populations low. Gill netting can be effective in lakes up to 2 hectares in size that are clear of debris (US Department of the Interior, 2003). However, gill nets may harm non-target species such as birds. Additionally,netting is labor and time intensive (Pfeifer et al., 2001). Electrojishing Electrofishing involves stunning and then capturing fish by applying electricity to water (Allen-Gil, 2000). This is a commonly used technique for fish surveys such as population counts. In terms of completefish removal, it appears that electrofishinghas had mixed results. Buktenica et al. (2001) successfullyreduced thepopulation of unwanted brook trout using diver-directed electrofishingover several years. Moore et al. (2001) indicatethat electrofishingis useful for reduction of targeted fish such as rainbow trout. Other sources indicatethat electrofishingmay not be useful for all fish types and that fish may sense the current and hide from netters. Injury to fish is possible with electrofishing,with one ofthe worst effects being broken backs. However, it is noted that in general there is no substantialimpact on the population. Several factors may result in variability in electrofishing effectiveness. These factors include fish species, size, and other fish characteristics,water temperature, time ofyear, and other factors (Temple and Pearsons, 2005). For example, large fish are more susceptibleto electrofishing than smaller fish (Allen-Gil, 2000). Electrofishing may be ineffective in complex stream habitats. It appears to be commonpractice to follow electrofishing with a piscicide application to ensure complete eradication.

Other Angling is described as ineffective way to control fish populations for several reasons,
one of which is that some species may not be susceptibleto angling (Finlayson et al,2000). Increased angling pressure appears to be somewhat successful for reducing unwanted fishpopulations from streams. This method is not effective for elimination of all fish 

### as smaller fish are generally not caught (Moore et al., 2005). Anglers are also less likely to reach isolated mountain streams. Increased anglingmay provide only temporary population reduction.

An article from Taiwan comparing rotenone to clove oil indicated that clove oil couldbe used to sample and collect fish, while keeping them alive, in subtropical intertidal areas (Wen, et al, 2005). However, it does not appear that this use of clove oil is registered in the U.S.

Economics
Piscicides The costs ofrotenone and antimycin A are comparable. The cost ofrotenone per acrefoot in 1998 varied from about $2 - 13 at low application rates and $45 

### - 137 at 

### high application rates, while the cost of antimycin A was about $47 per acre-foot (EPA proprietary data, 1998). The cost of applying these piscicides is generally more costly than the piscicides themselves dependingon the situation. Antimycin A has the advantage ofbeing active in smaller amounts and thus may be less costly to apply in remote areas.
GillNetting A study compared the costs of fish eradication using ofrotenone to that of gill netting in a small mountain lake (Knapp and Matthews, 1998). The total costs including application costs were comparable for both methods. However, most of the cost of rotenone was applying it by helicopter. Where economies of scale of applying rotenone by helicopter may be applicablein larger lakes, rotenone may be less costly than gill netting. Also, in less remote locations other application methods of applyingrotenone may be less costly than helicopter application; and therefore, less costly than gill netting.
Otherapplicationmethods We have not found costs for the alternativesthat could be compared to the cost ofusing piscicides. For example, some costs are availableusing electrofishing for samplingfish, but it is not clear what these costs would be for eliminating all fish 

### of a species. The costs of dewatering would vary widely from draining an aqua-culturepond to dewatering a large lake where significant capital costs could be incurred with excavation equipment and structures required to hold and to control the water.
Economic conclusion Because the costs, feasibility, and efficacy ofthe alternatives vary widely depending on the situation, we cannot concludewhich method is most cost effective. It depends on the situation.References
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Brunson, M.W., Last Modified 2004, Using Rotenoneto Renovate Fish Populations in Farm Ponds, Mississippi Stateuniversity Extension Service, Web address: 

### htt~://msucares.com/pubs/vublicationslv 1954.htm
Buktenica, M.W., 

### B.D. Mahoney, S.F. Girdner, and G.L. Larson, 2001. Response of resident bull trout population to nine years ofbrook trout removal, in Sun Creek, Crater Lake National Park, Oregon. Practical approaches for conserving native inland fishes of the west abstracts.Missoula, MT, 6-8 June 2001. Web Address: http://www 

### .fisheries.org~AFSmontana~Misc/Symposium%2OAbstracts/Abstracts.pdf.
Cichra, C.E, 2003. Managing Florida ponds for fishing. University of Florida IFAS. Web Address:

### httv://edis.ifas.ufl.edu/FAOOl



### . Finlayson, B. J., R. A. Schnick, R. L. Cailteux, L. DeMong, W. D. Horton, W. McClay, C. 

### W. Thompson, and 

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### htt~://www.fisheries.ordrotenone/Rotenone Manual.vdf

Great Lakes Fishery Commission, 2004, Larnpricides and Facts about Stream Treatments, Fact Sheet 4a, Web address: 

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### ht~://cbc.amnh.ordsynvosia~fieshwater/index.html
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### B. Curtis, 2001. Washington Department of Fish and Wildlife's High lakes fisherymanagement program. Web Address: 

### http://wdfw.wa.gov/fish/hinh lakeshigh lakes final vart2b.pdf.
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### http:Nwww.fisheries.org/AFSmontana~Misc/Symposium%2OAbstracts/Abs~acts.pdf. Temple, G.M. and T.N. Pearsons, 2005, Backpack and Drift Boat ElectrofishingDesign Considerations and SamplingProtocols, Washington Department of Fish and Wildlife, Web address: 

### http://~w~.vnamp.org//web/w0rk~o~v~/FPM~meeting~/2005 1205/2005 1202Electrofis hing.doc US Department ofthe Interior, 2003. Mountain lakes fisherymanagement environmental impact statement public scopingmeetings, March 2003. National Park Service,North CascadesNational Park ServiceComplex. Web Address: htt~://www.nvs.gov/archive/noca/Mtnlakeinl .htm.
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### revorts/Fossi1%2OCreek%2ORestoration.vdf
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### htt~://hgic.clemson.edu/factsheets/HGIC 17 13.htm Wynne, F., 2002, Removal of Undesirable Fishes from Warmwater Ponds, Kentucky State University CooperativeExtension Program, Accessed 2006, Web address: 

### http:llaquanic.ornlpublicat/state/k~/unwanted.htm